Apparatus for and method of making filter rods for filter tip cigarettes

ABSTRACT

Filter rods for filter tip cigarettes are cut from tows of cellulose acetate fibers. The tows are placed coaxially in front of a jet emitting continuously or intermittently a stream of compressed air which drives the tows successively against a detent. When the forward end of a tow abuts against the detent a movable circular knife is brought into position to sever a segment of the two therefrom. The knife is mounted at a predetermined distance from the detent, so that the portions of the two which are separated by the action of the knife are of uniform and precisely controlled length. Retraction of the knife following the cutting operation and lateral transport of the cut segments permits the uncut tow to advance by the force of the airblast until it rests at its forward end against the detent, whereby the operation is repeated.

United States Patent Inventors Otto Kappeler Trossingen; SiegfriedSudrow,/Bunzwangen, both of, Germany Appl. No. 850,072

Filed Aug. 14, 1969 Patented July 6, 197 l Assignee Efka-Werke FritzKiehn G.m.b.lll. Trosstngen, Germany APPARATUS FOR AND METHOD OF MAKINGFILTER RODS FOR FILTER TIP CIGARETTES 6 Claims, 2 Drawing Figs.

Primary Examiner-1ames M. Meister A!!0rney Nolte and Nolte ABSTRACT:Filter rods for filter tip cigarettes are cut from tows of celluloseacetate fibers. The tows are placed coaxially in front of a jet emittingcontinuously or intermittently a stream of compressed air which drivesthe tows successively against a detent. When the forward end of a towabuts against [1.5. [he detert a movable circular knife is brought intoposition to 33/160, 83/263, 33/281, 33/402, 83/417 sever a segment ofthetwo therefrom. The knife is mounted at hit. a predetermined distancefrom the deter so that the portions Field of Search 83/98, l 12, f th twwhich are eparated by the action fthe knife are of 269, 281, 402, 417uniform and precisely controlled length. Retraction of the knifefollowing the cutting operation and lateral transport of Rekrences Cmthe cut segments permits the uncut tow to advance by the UNITED STATESPATENTS force of the airblast until it rests at its forward end againstthe 2,005,589 6/1935 McCoy 83/269 UX detent, whereby the operation isrepeated.

e 2e o l 25 1 D 16 r 7" l7 2 a C O I 8 t r O r mr O O PATENTEU JUL 6I97! INVENTORS. OTTO KAPPELER BY SIEGFRIED SUDROW %%1 jz@eez ATTORNEYSAPPARATUS FOR AND METHOD OF MAKING FILTER RODS FOR FILTER TIP CIGARETTESThe present invention relates to an apparatus for, and method of, makingfilter rods for filter tip cigarettes, and particularly for makingfilter rods which are segments of a longitudinal tow of smoke-filteringfibers.

It is essential in the manufacture of such filter rods to minimize thephysical and temporal length of the supply path; this requirement,however, makes it difficult to precisely time the process and to controlthe length of the filter rods.

SUMMARY OF THE INVENTION It is, therefore, the primary object of thepresent invention to satisfy the respective requirements by providing asimple apparatus for, and method of, making filter rods for filter tipcigarettes which permit a precise measurement of the length of theindividual filter rods.

This object and other which will become apparent hereinafter areattained, in accordance with the present invention, by aligning the towsin spaced relationship in front of, and coaxial with an air jet to whichcompressed air is supplied from a source. The forward propulsion of thetows under the force of the compressed airblast is arrested by detentmeans disposed at a predetermined distance from the air jet. Cuttingmeans positioned intermediate the air jet and the detent are actuatableto sever the tows transversely of their length. The distance between thecutting means and the detend means precisely equals the desired lengthof the individual filter rods. In one preferred embodiment of theinvention the cutting means is a circular crosscut knife executing oneidling revolution after each cutting operation, whereby a specialworking rhythm is established during which uniform segments aresuccessively cut from a tow without waste motions and without a waste oftime.

According to a preferred embodiment, the detent means is formed by theouter wall of a sliding conveyor movable in a reciprocating manner in adirection perpendicular to the direction of the airblast. The conveyoris enclosed in a coaxial conduit. The wall of the conduit comprises, inthe region ofair jet, an aperture through which the forward end of thetow is admitted to abut against the outer wall of the sliding conveyor.The conveyor includes a bore transversely its length and ofsubstantially the same diameter as the aperture in the'conduit wall. Thereciprocating movement of the conveyor is synchronized with the movementof transport means which place the tows into position relative to theknife, and with the operation of the knife, so that following thecutting operation the conveyor is in its initial position wherein thebore is aligned with the aperture in the conduit wall. During thealignment the cut segment of the tow, of precisely the same length asthe final filter rod, is received in the bore and is subsequentlytransported therein to a precessing station. Removal of the cut segmentout of the path of the airblast permits the uncut tow to advance, sothat successively lengths of uniform filter rods are produced.

BRIEF DESCRIPTION OF THE DRAWING Filter rods for cigarette filters arecommonly produced from substantially cylindrical tows comprisingsynthetic fibers, especially cellulose acetate fibers. The tows are cutinto filter plugs or rods of predetermined length, which are insertedinto filter tubes attached to tobacco-filled cigarettes and cementedtherein.

In FIG. 1 there is shown a hopper 3 mounted on a rotatable drum 1 whichis attached to a frame 20. The bottom section of hopper 3 comprises anopen part 3a through which a portion of the drum 1 is admitted. Hopper 3is adapted to hold a supply of cylindrical tows 2 of acetate fibers insubstantially parallel alignment relative to one another. The drum I ismounted coaxially with a notched wheel I on shaft 2!. Rotation of thedrum I in the direction of arrow A is actuated by means of a striker 22which is supported in springs 23, and

which alternatingly engages and releases, by reciprocating motion,successive notches 24 on the periphery of wheel 1'. The springs 23 arealternatingly attracted and repulsed by a magnet ll" which is connectedto a motor 27, and which is energized, respectively deenergized thereby,as is well known. The angle of striker 22 in respect to the notches 24of wheel 1' is such that a forward stroke of the striker gives the wheela forward push to angularly displace it by a distance which puts thefollowing notch into position to receive another push in the indicateddirection during the following forward movement ofthe striker.

In an alternate embodiment of the present invention, which is indicateddiagrammatically in FIG. 1, the drum 1 is rotated by motor 27, theoutput shaft of which is linked by camming gear 28 of conventionalconstruction to the drum. A tension spring 25 is provided intermediatethe motor 27 and the drum 1; when an electric contact is close-d, thespring means 23 releases the drum by retraction of the striker 22, sothat the drum 1 can rotate through the predetermined angle. In thisembodiment the function of striker 22 is to arrest the movement of thedrum by engagement of the notches 24 of wheel El.

Drum ll comprises on its circumference a plurality of symmetricallyspaced U-shaped pockets 5. As the pockets 5 are moved successivelythrough the hopper 3 by rotation of the drum 1, one tow 2 after theother is scooped up in the successive pockets and is transported thereinalong a rotary path toward a position P (FIG. 2) in front of and coaxialwith a stream of compressed air which is supplied intermittently orcontinuously through a jet 6 by means not shown. At a predetermineddistance from the jet 6 detent means for the tows 2 are provided by theother wall of a sliding conveyor 7 which is movable perpendicular to theairstream in the horizontal direction. A circular crosscut knife 8 ismounted on the frame 20 at a point intermediate the detent means, thatis, the wall of conveyor 7 and the jet 6. The knife is rotatable in thedirection of arrow C, and is mounted, controlled and actuated by meansdenoted by the reference numerals 9, and 11 respectively which are notto be considered part of the present invention. In combination, theseelements make it possible to reciprocate the knife in the direction ofarrow D, so that, in synchronization with the rotation of drum 1 andwith the sliding movement of conveyor 7, the knife is lowered into thepath of the airstream, to cut a segment 14 from the two 2, and elevatedaway from the path and out of the way as a successive portion of tow isadvanced by the airblast.

The conveyor 7 is encased in a conduit 12 which includes, in the regionof the airstream, an aperture 13 through which the forward part of tow 2is admitted to abut against the outer wall of conveyor 7 inside theconduit. The conveyor 7 comprises a bore 15 transverse to its lengthwhich, in the initial position of the conveyor is coaligned withaperture 13 in the conduit 12, and forms an opening in which the cutfilter rod 14 is received as the airstream pushes against the tow 2 inthe pocket 5. When the conveyor 7 slides forward under the influence ofdrive means, not shown, the filter rod 2 in the bore 15 is transportedtherein, and a closed portion of the wall of conveyor 7 is broughtopposite the aperture 13 to form a detent for a succeeding portion oftow 2 prior to cutting.

A transport wheel 16 is mounted on the frame 20 parallel with drum lproximate to the longitudinal wall of conduit 12 opposite the wall whichis facing the airstream. The wheel 16 which is rotatable on a shaft 26comprises a plurality of tubular bores 17 which are equidistantly spacedin annular arrangement on its surface and extend parallel with shaft 26.During rotation of the wheel 16 (by means not shown) one of the bores 17after the other is brought into position to commu nicate with the bore15 of conveyor 7 when the latter is in its extreme forward or terminalposition. A pin-shaped pusher 18 which is mounted on the frame 26coaxiaily with the bores 17 and E5 in their coaligned position isreciprocated in the direction of arrow E (by means not shown), to pushthe filter rod M out of bore 15 into bore 17. The wheel I6 then carriesthe rod 14 through a rotary path of predetermined length to an ejectionstation 19 where the rod is removed and processed into a filter tube, asis well known.

The steps of the operation by which the filter rods are produced are asfollows: drum 1 is driven by actuation of the notched wheel 1' throughstriker 23, respectively by energization of the magnet 1''. Duringrotation of the drum 1 tows 2 are deposited in the pockets 5 on theperiphery of the drum and moved, one after the other, in front of an airjet 6. The force of compressed air emitted through the jet propels thetow in a forward direction until it passes through an aperture 13 in thewall of conduit 12 to abut against the outer wall ofa sliding conveyor 7which is coaxially reciprocable in the interior of the conduit. Held inplace thereby, the tow 2 is cut transversely ofits length by a circularknife 8 which is positioned at a location intermediate the jet 6 and thedetent means provided by the wall of conveyor 7. The knife 8 is actuatedby drive means 11 and controlled by means to sever a portion ofpredetermined length from the tow 2, proportional to the length of thefinal filter rod 14.

The length of the cut filter rod is independent of the length of thetow. As the sliding movement of the conveyor 7 aligns the bore in theconveyor with the aperture 13 in the conduit wall and with the directionof the airblast, the cut filter rod 14 is received in the interior ofthe conveyor 7 and laterally transported therein, so that a successiveportion of the uncut tow is moved into the place previously occupied bythe cut segment. The forward transport of the conveyor moves a portionof the wall of the conveyor 7 opposite the frontal part of the uncut tow2 to form detent means therefor, prior to the cutting operation. In thisway the process is repeated until a tow 2 has been separated into parts14 of equal length. If any remnant of a tow should be left over it willbe blown aside by the airblast; lengths of tow which are less than thespecified length of the final filter rod cannot enter the bore 15 of theconveyor 7, since the bore is always occupied by a cut filter rod. Thedistance between the pocket 5 of the drum 1 and the detent means isprecisely controlled, so that a portion of a tow which is shorter thanthe correct length will not be held in the required alignment relativeto the knife.

Although preferred embodiments of the invention have been illustratedand described, many modifications thereof will be obvious to thoseskilled in the art. Accordingly, the invention should not be limitedexcept as defined by the following claims.

What we claim is:

ll. An apparatus for making filter rods for filter tip cigarettes fromlongitudinal tows of smoke-filtering material comprising a frame, ahopper for said tows, a source of compressed air, means for injectingcompressed air from said source along a straight path across said frame,transport means for collecting said tows from said hopper and moving thesame from said hopper laterally in spaced relationship into said pathand coaxial therewith, a conveyor adjacent to said transport means,detent means mounted on said frame limiting said path, cutting meansattached to said frame and movable thereon between a first position awayfrom and a second position into said path, for cutting segments of saidtows therefrom transversely of their lengths, and said compressed airsource propelling the cut segments of said tows on said conveyor.

2. An apparatus as defined in claim 1 wherein said cutting means is acrosscut circular knife positioned relative to said detent means at adistance which is proportional to the length of each ofsaid filter rods.

3. An apparatus as defined in claim 1 wherein said detent means isformed by said conveyor reciprocatingly slidable in a direction normalto said path of compressed air.

t. An apparatus as defined in claim 3 wherein said conveyor comprises atubular bore extending therethrough transversely of its longitudinalaxis, said tubular bore being adapted to receive a cut segment ofsaidtows.

5. An apparatus as defined in claim 4 further comprising a hollowconduitcoaxial with and enclosing said conveyor, said conduit comprisingan aperture at a location opposite said source of compressed air andadapted to communicate with said bore in said conveyor only in theinitial position thereof, wherein said out segments of said tows arereceived in said conveyor.

6. An apparatus as defined in claim I wherein said transport means is arotatable drum having a plurality of spaced pockets on the circumferencethereof for receiving said tows from the hopper.

1. An apparatus for making filter rods for filter tip cigarettes fromlongitudinal tows of smoke-filtering material comprising a frame, ahopper for said tows, a source of compressed air, means for injectingcompressed air from said source along a straight path across said frame,transport means for collecting said tows from said hopper and moving thesame from said hopper laterally in spaced relationship into said pathand coaxial therewith, a conveyor adjacent to said transport means,detent means mounted on said frame limiting said path, cutting meansattached to said frame and movable thereon between a first position awayfrom and a second position into said path, for cutting segments of saidtows therefrom transversely of their lengths, and said compressed airsource propelling the cut segments of said tows on said conveyor.
 2. Anapparatus as defined in claim 1 wherein said cutting means is a crosscutcircular knife positioned relative to said detent means at a distancewhich is proportional to the length of each of said filter rods.
 3. Anapparatus as defined in claim 1 wherein said detent means is formed bysaid conveyor reciprocatingly slidable in a direction normal to saidpath of compressed air.
 4. An apparatus as defined in claim 3 whereinsaid conveyor comprises a tubular bore extending therethroughtransversely of its longitudinal axis, said tubular bore being adaptedto receive a cut segment of said tows.
 5. An apparatus as defined inclaim 4 further comprising a hollow conduit coaxial with and enclosingsaid conveyor, said conduit comprising an aperture at a locationopposite said source of compressed air and adapted to communicate withsaid bore in said conveyor only in the initial position thereof, whereinsaid cut segments of said tows are received in said conveyor.
 6. Anapparatus as defined in claim 1 wherein said transport means is arotatable drum having a plurality of spaced pockets on the circumferencethereof for receiving said tows from the hopper.